If $x \veebar y = 3x^{2}-y^{2}$ and $x \star y = 2x-7y$, find $(3 \veebar 0) \star 3$.
Explanation: First, find $3 \veebar 0$ $ 3 \veebar 0 = 3(3^{2})-0^{2}$ $ \hphantom{3 \veebar 0} = 27$ Now, find $27 \star 3$ $ 27 \star 3 = (2)(27)-(7)(3)$ $ \hphantom{27 \star 3} = 33$.